Just got my AutoProm!

[Fast355]

Maybe its normal then... It's mainly when its cold... Seems to be not as bad once warmed up. It's just kind of maddening to stop for coffee on the way to work and have it sitting there revved up to 1000 rpm for no reason...

is there any way to make it idle a little lower? 800ish maybe?

Its been forever but I believe the 7747 has a table for desired IAC steps and a "kickdown" value. You can tweak on the IAC steps vs coolant temperature table. When you change things with the engine or alter settings like the spark advance, you throw the factory calibration out of line.

Perhaps post a datalog and the .BIN and we will look at it.

[EagleMark]

Maybe its normal then... It's mainly when its cold... Seems to be not as bad once warmed up. It's just kind of maddening to stop for coffee on the way to work and have it sitting there revved up to 1000 rpm for no reason...

is there any way to make it idle a little lower? 800ish maybe?

Yes there are ways and as Fast mentioned other tricks and some can go bad.

Post bin and log with it happening then full warm up.

[Xenon]

Will do. Thanks.

[Xenon]

Well I made a datalog, but it didnt do it as bad as it has been, I'm guessing because its warmer out today?

Even once its warmed up it doing it though... Idling at 850 when target is 625.

This truck has a straight through 3" exhaust with 36" glasspack muffler so idling at 850 is annoying for me and everyone else around.

.bin and datalog attatched. DFCO and PE are turned on, Didnt think it mattered for logging an idle problem. Lemme know if Im wrong.

[EagleMark]

Need some data of IDle at end of log in drive! I think you do have an IAC issue.

[Xenon]

Oops! And I know that! Always one minute of drive and one minute of park

will do that and post up shortly. Thanks.

[Xenon]

Ok, got a few minutes of in gear idle and a few in park. If you need something else lemme know.

Thanks!

[EagleMark]

So far everything is working as it should. If you don't like it to be higher RPM when cold then that takes some tuning and I don't recommend it!

BUT! The reason it's idling at 800 in park after being 650 in drive is because the IAC count is SO high when the engine is idling in drive. 40-42? Then 51 in Park! Turn your throttle blade stop screw, also known as Min AIr Screw and never known as an Idle screw... in 1/2 a turn and things should be much better. This will get IAC counts down, then park/neutral will come down as well. WIll also allow more air to mix with fuel over throttle blades helping idle quality!

Only judge IAC counts at end of warmed up driven data log. You may have to do this again.

But! Your TPS voltage is already high at .74, this is about max I like to see. Factory says .54 and I've never seen any reason it can't be higher to a point around 1.0 volt. But to high and the ECM looses the bit switch from Idle to Off Idle. So you may have to use a file and oblong holes in TPS sensor to turn it far enough to get the voltage down after you turn screw in. Turning screw in raises voltage even more...

[Xenon]

Ok, thanks for the help!

[EagleMark]

Looking at you idle has me thinking you may not need a new cam? Idle MAP is up a little like an aftermarket cam, but not ridicules. I'm wondering if your off idle power BLAH could not be improved with some tuning/spark?

Where's Fast when you need him?

[Xenon]

Id be all for that... Open to all suggestions...

[Fast355]

Looking at you idle has me thinking you may not need a new cam? Idle MAP is up a little like an aftermarket cam, but not ridicules. I'm wondering if your off idle power BLAH could not be improved with some tuning/spark?

Where's Fast when you need him?

Why was I thinking this motor had a cam. Also what heads casting is it running? If its an 882 or 993 or other open chamber smog head and running a stock dished piston it could very well be as low as 8:1 compression. Larger duration cams would certainly make the low-end soggy. 882 heads need lots of timing.

[Xenon]

Don't remember the casting number for sure, but I cc'd everything when I got it and figured it was 8.6:1 compression.

Only reason I'm figuring it has a cam for a lighter application is the low-ish vacuum and tha lack of low end torque. Figured it was build for a camaro or something... Never knew the guy who had it built.